Method for pre-operative visualization of instrumentation used with a surgical guide for dental implant placement

ABSTRACT

The invention relates to manufacturing a surgical guide to be placed in a patient&#39;s mouth. The patient&#39;s mouth is scanned to obtain surgical-region scan data at a region where an implant is to be located. The patient&#39;s mouth is also scanned in the opened position to acquire dental conditions opposite from the surgical region so as to obtain opposing-condition scan data. A virtual model is developed using the surgical-region scan data and the opposing-condition scan data. Using the virtual model, a surgical plan is developed that includes the location of the implant to be installed in the patient. A virtual surgical guide is also developed based on the surgical plan. The dimensions of instrumentation to be used with the surgical guide are checked to ensure they will fit within the mouth by use of the opposing-condition scan data. After checking, final surgical-guide manufacturing information is obtained for manufacturing the surgical guide.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/526,717 filed Jun. 19, 2012, which is a continuation of U.S. patentapplication Ser. No. 13/179,609, filed Jul. 11, 2011, which is acontinuation of U.S. patent application Ser. No. 12/425,202, filed Apr.16, 2009, which claims the benefit of U.S. Provisional Application No.61/124,331 filed Apr. 16, 2008, both of which are hereby incorporated byreference in their entireties.

FIELD OF INVENTION

The present invention relates generally to use of CAD-CAM methodologiesfor installing dental implants. More particularly, the present inventionrelates to a method for pre-operative visualization of the location andpositions of instrumentation that will be used with a surgical guide inplacing a dental implant.

BACKGROUND OF THE INVENTION

The dental restoration of a partially or wholly edentulous patient withartificial dentition is typically done in two stages. In the firststage, an incision is made through the gingiva to expose the underlyingbone. After a series of drill bits creates an osteotomy in the bone, adental implant is placed in the jawbone for integration. The dentalimplant generally includes a threaded bore to receive a retaining screwholding mating components therein. During the first stage, the gumtissue overlying the implant is sutured and heals as theosseointegration process continues.

Once the osseointegration process is complete, the second stage isinitiated. Here, the gum tissue is re-opened to expose the end of thedental implant. A healing component or healing abutment is fastened tothe exposed end of the dental implant to allow the gum tissue to healthere around. Preferably, the gum tissue heals such that the aperturethat remains generally approximates the size and contour of the aperturethat existed around the natural tooth that is being replaced. Toaccomplish this, the healing abutment attached to the exposed end of thedental implant has the same general contour as the gingival portion ofthe natural tooth being replaced.

During the typical second stage of dental restoration, the healingabutment is removed and an impression coping is fitted onto the exposedend of the implant. This allows an impression of the specific region ofthe patient's mouth to be taken so that an artificial tooth isaccurately constructed. After these processes, a dental laboratorycreates a prosthesis to be permanently secured to the dental implantfrom the impression that was made.

In addition to the more traditional system for placing dental implantsdescribed above, some systems use guided placement of the dentalimplants. In these situations, a surgical plan is developed for thepatient that will include the location and orientation of the implantsto be installed by a surgical guide. Once the surgical plan is known,the surgical guide can be developed and, eventually, placed in thepatient's mouth at the known location. The surgical guide includesopenings for providing the exact placement of the drill bits used tocreate the osteotomy. Once the osteotomy is completed, the surgicalguide may permit the dental implant to be placed through the sameopening and enter the osteotomy that was guided by the surgical guide.

Surgical guides can be created by the use of a CT-scan of the patient'smouth. The CT-scan provides enough detail to develop the surgical guideby use of various methods. For example, a CT-scan can provide thedetails of the patient's gum tissue and/or remaining teeth so that thesurgical guide can be developed based on computer-aided design (CAD) andcomputer-aided manufacturing (CAM). One example of the use of a CT-scanis disclosed in U.S. Patent Publication No. 2006/0093988, which isherein incorporated by reference in its entirety. This publication alsodescribes the use of various tubes that can be placed within thesurgical guide to receive the drill bits and implants.

However, some problems may occur with the development and manufacturingof the surgical guide. For example, the surgical plan may require theuse of a certain sized implant, dental drill, or other components thatmay not fit well in the patient's mouth due to the opposing (i.e., upperor lower) teeth and/or gum tissue in the patient's mouth. Thus, theclinician may be disappointed because of the considerable amount of timeand effort in planning the case, only to need a revised plan andpossibly a new surgical guide. The patient, of course, is alsodisappointed because he or she did not receive what was expected in thatvisit (possibly a temporary prosthesis) and will be forced to return anadditional day to complete the project.

As such, a need exists to develop an improved CAD-CAM relatedmethodology for developing a surgical plan and a surgical guide that isused in accordance with the surgical plan.

SUMMARY OF THE INVENTION

In one aspect, the present invention is a method of manufacturing asurgical guide to be placed in a patient's mouth, comprising scanning apatient's mouth to obtain surgical-region scan data in a surgical regionat which at least one dental implant is to be located, scanning apatient's mouth in the opened position to acquire dental conditionsopposite from the surgical region so as to obtain opposing-conditionscan data, and developing a virtual model of the patient's mouth usingthe surgical-region scan data and the opposing-condition scan data. Themethod further includes developing, with the use of the virtual model, asurgical plan that includes the location of the at least one dentalimplant to be placed in the mouth of the patient, developing a virtualsurgical guide based on the location of the at least one dental implantand the surgical-region scan data, and checking the dimensions ofinstrumentation to be used with the surgical guide to ensure theinstrumentation will fit within the patient's mouth by use of theopposing-condition scan data. After the checking step, the methodincludes obtaining final surgical-guide manufacturing information basedon the virtual model, and manufacturing the surgical guide based on thefinal surgical-model manufacturing information.

In another aspect, a method of manufacturing a surgical guide to beplaced in a patient's mouth, comprises developing a virtual model of thepatient's mouth using scan data from the patient's mouth, anddeveloping, with the use of the virtual model, a surgical plan thatincludes the location of multiple dental implants to be placed in themouth of the patient. The surgical plan includes a surgical protocol ofinstrumentation to be used to install the multiple dental implants. Themethod further includes developing a virtual surgical guide based on thesurgical plan and, by use of opened-mouth scan data from an opened-mouthcondition from the patient's mouth, determining an available dimensionfrom the virtual surgical guide to dental structures that are opposingeach of the multiple dental implants. In response to the availabledimensions being less than a dimension for the instrumentation to beused with each of the multiple dental implants, the method includesaltering the surgical plan, obtaining final surgical-guide manufacturinginformation based on the virtual model after the altering, andmanufacturing the surgical guide based on the final surgical-modelmanufacturing information.

According to a further aspect of the invention, a method of developing asurgical guide to be placed in a patient's mouth comprises developing,with the use of a virtual model from the patient's mouth, a surgicalplan that includes the location of multiple dental implants to be placedin the mouth of the patient. The surgical plan includes a surgicalprotocol of instrumentation to be used to install the multiple dentalimplants. The method further includes developing a virtual surgicalguide based on the surgical plan, and by use of opened-mouth scan datafrom an opened-mouth condition from the patient's mouth, determining anavailable dimension from the virtual surgical guide to dental structuresthat are opposing each of the multiple dental implants. Further, themethod includes comparing the available dimensions to dimensions for theinstrumentation, and altering at least one of (i) the instrumentation,(ii) the virtual surgical guide, (iii) the implant size, and/or (iv) theimplant location in response to the dimensions for the instrumentationbeing greater than the available dimensions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a scan of a patient's mouth with the mouthclosed;

FIG. 2 is a front view of a scan of the patient's mouth with the mouthopened;

FIG. 3 illustrates a virtual image of the patient's mouth, and asurgical guide to be used in accordance to a surgical plan;

FIG. 4 is an illustration of a side view of a surgical drill that is tobe used in accordance with the surgical plan;

FIG. 5 is an illustration of a side view of a dental implant and adental implant mount that are to be used in accordance with the surgicalplan;

FIG. 6 illustrates a virtual image of the patient's mouth using thesurgical plan, with the dental implant of FIG. 5 and the surgical drillof FIG. 4 being displayed relative to the surgical guide;

FIG. 7 illustrates the actual surgical guide of FIGS. 3 and 6 after ithas been manufactured;

FIG. 8 illustrates a kit containing various components that are usedwith the surgical guide to create an osteotomy in the patient's mouthand to install a dental implant;

FIG. 9 illustrates the surgical guide of FIG. 7 after it has been placedin the patient's mouth, along with a drill bit that is used to developan osteotomy;

FIG. 10 illustrates the surgical guide of FIG. 7 after it has beenplaced in the patient's mouth, along with a dental implant that is beinginstalled in the osteotomy; and

FIG. 11 illustrates a flow chart of the process used to develop thesurgical plan and the surgical guide.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed but, on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 illustrates a first scan 10 of a patient's mouth with the mouthin a closed position. In this example, the patient is in need ofmultiple dental implants in the lower jawbone. Multiple scans may betaken from the sides to obtain scan data reflecting the entire conditionof the lower jawbone. The scanning of the patient's mouth may beachieved by a CT scanner (or other scanning technologies or devices) toobtain scan data regarding the details of the bone structure, teeth andoverlying gingival tissue. The first scan 10 usually involves a scanningappliance that is placed in a patient's mouth. As is known in the art, ascanning appliance is used for a partial or fully edentulous patient andincludes physical shape information representing the desired prostheticteeth in the region, usually with added material (e.g., barium sulfate)that can be picked-up by a typical CT scan.

The first scan 10 of the patient's mouth is useful in developing asurgical plan for the patient. When considering a dental surgical planfor a specific patient, the location and orientation of the implantsrelative to the surface of the gingival tissue, remaining teeth, and theunderlying bone is important. Additionally, the maximum depth of thedistal end of the implant within the bone is also important to thesurgical plan, so as to avoid the sinus cavity and mandibular canal. Aswill be discussed in more detail below, the surgical plan will dictatethe development of the surgical guide that fits snugly onto the surfaceof the tissue by having a negative impression that incorporates thedetails of the tissue surface in the patient's mouth. By the term“tissue” in the present specification, it is understood that tissue canbe hard tissue (such as bone tissue or teeth) and soft tissue (such asthe gingival tissue).

FIG. 2 illustrates a second scan 20 of the patient's mouth with themouth in the opened position. Bite blocks may be used to assist thepatient in holding his or her mouth in the opened position. If thepatient is wearing a removable denture in the jaw opposing theimplant-receiving region, then they would remove it during the secondscan 20. Like the first scan 10 of FIG. 1, the second scan 20 may beachieved by a CT scanner that produces scan data that can be entered ordownloaded into a computer for developing the surgical plan. As will bedescribed in detail below, the second scan 20 allows the surgical planto take into account the spatial constraints within the mouth of thatparticular patient. In other words, the scan second 20 providesdimensional limitations to be measured between the opposing dentalstructure (e.g., teeth and/or gingival tissue) and the surgical guidethat will be placed on the lower jawbone in this particular patient.

FIG. 3 illustrates a virtual model 30 of the patient's mouth that hasbeen derived from the scan data from FIG. 1 and the opened-mouth scandata from FIG. 2. In particular, the virtual model 30 is shown on acomputer display 35 and includes the upper jaw (maxillary) 40 and thelower jaw (mandible) 45. The relative dimensions between the upper jaw40 and the lower jaw 45 are derived from the second scan 20 of thepatient's mouth in the opened position. Additionally, a virtual surgicalguide 50 is located on the lower jaw 45 and includes virtual openings 52that have been established for receiving instrumentation, such as tissuepunches, drill bits, counter sinks, and the dental implant that isneeded for surgery. The surgical guide 50 is developed based on thedesired locations in the lower jaw 45 of the dental implants asdetermined by the first scan 10 from the patient's mouth. Thus, prior tothe display of the virtual surgical guide 50, the technician working onthis case for the patient would have placed various sizes of virtualimplants at ideal locations and orientations in the lower jaw 45 forproperly supporting a prosthesis, such as a denture or a partialdenture. The technician chooses the sizes of the dental implants, aswell as their locations and angles, based on the various bone densitiesand underlying tissue (e.g., sinus cavity or mandibular canal) providedby the scans 10 and 20. One example of the display of the virtualimplants is shown in FIG. 6.

Based on the virtual model 30, the height dimension between the top ofthe virtual surgical guide 50 and the opposing dental structures (inthis case, teeth) can be easily determined. As shown, the heightdimensions H1, H2, H3 and H4 are provided for four openings 52 in thevirtual surgical guide 50 and generally correspond to the maximum heightfor instrumentation that will be permitted in the mouth of thisparticular patient due to the second scan 20 from FIG. 2. These heightdimensions H1, H2, H3 and H4 are measured along the axis of the opening,which is also coincident with the axis of the planned virtual implantfor that site. Thus, because the implants may not be installed in aparallel fashion due to constraints such as adjacent teeth or inadequatebone densities in certain regions of the patient's mouth, the directionof measurement of the height dimensions H1, H2, H3 and H4 may not beparallel either.

As an example, a virtual model 30 may include a hand depiction 60 of theclinician and, more importantly, a virtual drill bit 65 attached to avirtual hand piece 67 that may be needed for drilling the osteotomy forthe implant to be inserted through the openings 52 corresponding toheight dimension H3. If the height dimension H3 is less than the lengthof the instrumentation necessary to complete the implant installation onthe virtual model, then alterations must be made to be surgical plan sothat the instrumentation will fit within the patient's mouth at eachsurgical location. Examples of such alterations may include (i) changesto the size of the implant or the implant mount, (ii) changes to thelocation (e.g., angular orientation and/or position) of the implant inthe bone, (iii) changes to the surgical guide, and/or (iv) changes tothe instrumentation that is to be used for a certain implant.

The surgical planning software may utilize different points of referenceother than the exterior surface of the virtual surgical guide 50 whencomparing the dimensions. For example, the surgical planning softwaremay simply place the master tubes (see FIG. 7) within the virtual model30 and measure along the central axis from the top of the master tubes.Alternatively, the surgical planning software may utilize some roughestimation for height and thickness dimensions of certain types ofsurgical guides and make the determination using the estimated heightand/or thickness of the surgical guide. While this latter option doesnot present an exact calculation, the estimation may be enough to ensurethat the instrumentation will fit within the patient's mouth.

When determining whether the instrumentation will fit for each implant,the software program may simply choose the required instrument havingthe longest length (e.g., longest drill bit) or combination ofinstruments having the longest total length (e.g., implant, implantmount, surgical hand piece). If the instrument having the longest lengthwill fit into the patient's mouth for that particular implant site, thenall remaining instruments for that particular implant site should fit aswell. As used herein, it should be understood that “instrument” and“instrumentation” can mean a single component (e.g. drill bit) ormultiple components that are coupled together (e.g., driver plus drillbit, or implant, implant mount and surgical hand piece).

FIG. 4 illustrates the virtual drill bit 65 and the associated powerdriven hand piece 67 along with their respective tool length dimensions,T1 and T2. These dimensions, T1 and T2, are stored within memory devicesaccessible by the software program that is used in association with thevirtual model 30. These dimensions T1 and T2 can be compared against themaximum height dimensions (H1, H2, H3, H4) in the virtual model 30 toensure that the drill bit 65 can fit within the patient's mouth duringthe actual surgery. Similar dimensions would also be stored for othersizes of drill bits as well. Further, while FIG. 4 illustrates just onetype of tool (e.g., a drill bit 65) dimensions of the various types oftools (taps, countersinks, etc.) needed for surgery would also be storedin the memory device associated with the software program that is usedto conduct the virtual modeling.

FIG. 5 illustrates a virtual dental implant 70 having an internalanti-rotational feature 72. The virtual dental implant 70 is connectedto a virtual implant mount 80 with a screw such that the internalanti-rotational feature 72 mates with a corresponding anti-rotationalfeature 82 on the implant mount 80, just as occurs in an actual dentalimplant. The implant mount 80 includes an upper flange 86 with slots 87aligned with the anti-rotational feature 82 such that the orientation ofthe anti-rotational feature 72 of the implant 70 can be visualized by aninspection of the slots 87. The implant mount 80 includes an upperdriving portion 89 that attaches to a virtual power-driven dental device90, such as a dental hand piece. For purposes of virtual modeling, thesedetails of the implant 70 and implant mount 80 are not necessary.However, they have been included in FIG. 5 to provide insight as to theconstruction of the implant 170 and implant mount 180 as discussed inmore detail below relative to FIGS. 8-10.

FIG. 5 generally illustrates the length of the combination of thevirtual implant mount 80 and the implant 70 as I1 and the length of thevirtual power-driven dental device 90 as I2. These dimensions, I1 andI2, are stored within a memory device accessible by the computer programthat is used in association with the virtual model 30. Accordingly,these dimensions I1 and I2 can be compared against the maximum heightdimensions (H1, H2, H3, H4) in the virtual model 30 to ensure that theimplant 70 and its associated implant mount 80 can fit within thepatient's mouth during the actual surgery. Preferably, images of theimplant 70, the implant mount 80, and the power driven dental device 90are also stored in memory device so that virtual representation of thecomponents can be provided on the display 35 to the technician workingon the virtual model.

Because the surgical plan involves the placement of the implant 70 at acertain depth below the surgical guide, the implant mount 80 is providedin various lengths. In actual surgery, the depth of penetration of thecombination of the implant and the implant mount is limited by thesurgical guide and, specifically, the master tubes surrounding theopenings in the surgical guide that engage the flange on the implantmount, as is discussed below. Accordingly, as just one example of analteration of the surgical plan, if the combined height of the implant70 and its associated implant mount 80 exceeds the maximum heightdimension (e.g., H3), the implant mount 80 may be selected to have ashorter length such that the top of the implant 70 does not penetrate asdeep into the bone as would occur with the originally selected implantmount.

FIG. 6 illustrates an alternative display of the virtual model 30 ofFIG. 3. FIG. 6 illustrates the virtual surgical guide 50 and eightvirtual implants 70 a, 70 b, 70 c, 70 d, 70 e, 70 f, 70 g, 70 h. Thesize and locations of the virtual implants 70 are determined inaccordance with the surgical plan, as dictated by the first scan 10 ofthe patient's lower jaw. Once the locations and sizes of the virtualimplants 70 are determined, the virtual surgical guide 50 is developedwith an underside surface that will fit over and mate with the patient'sgingival tissue and/or remaining teeth in the lower jaw bone. FIG. 6also illustrates the use of the drill bit 65 of FIG. 4 and theinstallation of a certain dental implant 70 b. As can be seen, theoverall height dimensions of these two instruments can be compared withthe corresponding maximum height dimensions (shown in FIG. 3 as H2 andH4) for virtual implant 70 b and 70 h, respectively. Thus, it is notnecessary to show the image of the upper jaw bone 40 of FIG. 3 to makethe necessary comparison of dimensions.

FIG. 7 illustrates the actual surgical guide 110 that is manufactured inaccordance to standard CAD-CAM techniques based on the virtual surgicalguide 50. The surgical guide 110 can be produced from various materialsand techniques. One preferred method is using a rapid-prototypingtechnique. Because there is a need for eight implants, the surgicalguide 110 includes eight openings, each of which is defined by a mastertube 120 that is integrated into the material of the surgical guide 110with the assistance of the outer roughened surface and adhesive. Themaster tubes 120 are located on flat surfaces 122 that are substantiallyflush with the top surface of the master tubes 120. The master tubes 120have notches 124 that can be aligned with the slots 87 on the flange 86of the implant mount 80 to dictate the exact location of theanti-rotational feature of the implant when installed in the patient'smouth. The under portion of the surgical guide 110 (not visible in FIG.7) has a contour that follows the scan 10 (FIG. 1) of the gingivalsurface and/or remaining teeth in the patient's lower jaw bone. In otherwords, the under portion of the surgical guide 110 is a negativeimpression of the patient's conditions in the lower jaw bone. Thesurgical guide 110 also includes a plurality of openings 128 throughwhich temporary fixation screws or pins can be placed. The temporaryfixation screws or pins engage the bone and hold the surgical guide 110in the proper location so that the surgical plan can be executed usingthe surgical guide 110.

As can be seen, the actual surgical guide 110 and the image of virtualsurgical guide 50 on the display 30 may have a slightly differentappearance because the virtual surgical guide 50 was only fordetermining the available dimensions. In other words, the virtualsurgical guide 50 is more of a schematic illustration for purposes ofdetermining the available dimensions. Whereas the flat surfaces 122 onthe actual surgical guide 110 are variables chosen to accommodate thedifferent lengths of the implant amounts that are available forattachment to a specific dental implant, the actual locations of theflat surfaces 122 on the virtual model can be accounted for in thedimensional comparison. Alternatively, the present inventioncontemplates the display of a virtual surgical guide 50 on the display30 that is identical to the structure of the actual surgical guide 110.

Further, while the surgical guide 110 has been described relative to theuse of a surgical plan with eight dental implant, the present inventionis also useful for developing and installing single implants. Thus, thesurgical guide 110 may be smaller such that it only covers a limitedportion of the dental arch. The surgical guide 110 could be used forinstalling implants that support a multi-tooth prosthetic device or afull denture.

FIG. 8 illustrates a surgical kit 150 that contains the instrumentationthat may be used to conduct the surgery with the surgical guide 110. Itis these instruments that have dimensions (and preferably images) thatare stored within the memory devices used with the software program forthe virtual modeling. More details of the surgical kit 150 and themethods of using the surgical kit 150 in accordance with a surgical planare disclosed in U.S. Patent Application Ser. No. 61/003,407, filed Nov.16, 2007, and described in Biomet 3i's Navigator™ system productliterature, “Navigator™ System For CT Guided Surgery Manual” that ispublicly available, both of which are commonly owned and hereinincorporated by reference in their entireties.

In FIG. 8, the lower portion of the surgical kit 150 includes the boneprofilers 160 for shaping the bone surface at the osteotomy. The lowerportion of the surgical kit 150 also includes implant mounts 180 ofvarious sizes. For example, for each of the 3 mm, 4 mm, and 5 mmdiameters of the implant mounts 180 for mating with correspondinglysized implants, the available lengths are 7.5 mm, 9.0 mm, 10.5 mm, and12.0 mm. The surgical plan may require a set of implants havingdifferent lengths and that are positioned at different depths in thebone. Thus, the various lengths of the implant mounts 180 are needed toaccommodate those dimensional variables in accordance with the surgicalplan.

The upper portion of the surgical kit 150 in FIG. 8 includes drill bits165, which may include taps for creating female threads within theosteotomy. Each of the drill bits 165 is of a different size in thelength dimension (rows A, B, C, D, and E) and diametric dimension (e.g.,2.0 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.85, mm, 4.25 mm). Each drill bit 165has a stop flange that engages the top surface of guide tubes tools 190(discussed below) that fit within master tube 120 of the surgical guide110 (FIG. 7) to control its depth of insertion. Thus, when the surgicalplan is finally established (after comparison of the height dimensionsdiscussed with reference to FIGS. 3-6), a specific series of drill bits165 is chosen to be sequentially used with the surgical guide 110. Forexample, for a certain dental implant to be installed, the dental planmay call for the drill bits of B-2.0 mm and B-3.25 mm. The dimensions ofthe osteotomy are defined by the last drill bit (B-3.25 mm), which has adrill bit length dimension that accommodates the installation of thatcertain dental implant.

The surgical kit 150 also includes the guide-tube tools 190 that fitwithin the master tubes 120 to help receive the tools and implant. Eachof the guide-tube tools 190 includes a handle region to be manuallygrasped. At both ends of the guide-tube tools 190, there are guide tubesthat have a bushing-like structure. The purpose of the guide-tube tools190 is for mating within the master tube 120 of the surgical guide 110and, once properly seated in the master tube 120, to receive one or moreof the drill bits 165 used to create the osteotomy. Because creation ofthe osteotomy pursuant to the surgical plan calls for a sequence ofseveral drill bits 165 having different diameters, the guide-tube tools190 have different diameters to engage the drill bits 165 in arelatively tight fashion to prevent the drill bit from drilling at thewrong angle. Thus, for each diameter of a drill bit 165, there is acorresponding guide-tube tool 190. Further, because the master tubes 120in the surgical guide 110 may come in different sizes to receivedifferent sized implants, the guide-tube tools 190 may have differentouter diameters for mating with the different sized mater tubes 120. Asan example, the lower two guide-tube tools 190 may only be used with amaster tube 120 with a 5.1 mm inner diameter.

The surgical kit 150 further includes tissue punches 202 for removal ofa known size of gingival tissue from beneath the openings in thesurgical guide 110. The surgical kit 150 also includes starter drills204, such as drill bits for creating a pilot hole and, possibly,countersinks for creating a certain shape to the opening of theosteotomy. The surgical kit 150 may include other types of tools such asimplant holders 208 for holding the implants as they are mated with thecorrect implant mounts 180 and wrenches/drivers 206 for engaging thedriving element of the implant mount 180. The surgical kit 150 ispreferably made of any material that allows it to be sterilized via anautoclave.

FIGS. 9-10 provide a series of illustrations in which the surgical guide110 is used to place the actual dental implants 170 within the patient'smouth in accordance with the pre-established dental surgical plan thatlocated the virtual implants 70. As mentioned previously, a surgicalguide 110 was created through a technique that allows it to have anegative impression of the tissue surface within the patient's lower jawbone. Accordingly, after it has been developed, the surgical guide 110can be installed into the patient's mouth such that it fits snugly overthe gingival tissue or teeth or bone. The surgical guide 110 is held inplace in the patient's mouth by use of small, temporary fixations screwsor pins 225 that fit through the openings 128 in the surgical guide 110.Once it is fixed in place, the surgical guide 110 is used to conductsurgery in accordance to the dental plan discussed above.

FIG. 9 illustrates the use of a certain guide-tube tool 190 that fitswithin one of the master tubes 120 of the surgical guide 110. Theguide-tube tool 190 then receives a first drill bit 165 (for example, apilot drill) that is powered by a driver. Because of the various fluidsand materials that can build up during the surgery within patient'smouth, a suction tube 230 is often employed.

FIG. 10 illustrates the placement of one of the dental implants 170,which has been attached to a specifically-sized implant mount 180 inaccordance to the surgical plan. In particular, the implant 170 has beenscrewed into the bone by use of a tool that engages the driving elementof the implant mount 180. Because the underlying anti-rotational feature172 of the implant 110 (the same as anti-rotational feature 72 of theimplant 70 in FIG. 5) is aligned with the notch 187 of the flange 186 ofthe implant mount 180, the non-rotational feature 172 is oriented in theexact location defined by the dental surgical plan by aligning the notch187 of the implant mount 180 with the notch 124 in the master tube 120.A tool 240 may be used to detect the alignment of the notch 124 and thenotch 187. As discussed previously, because the implant mount 180 has aknown length, the exact depth of the implant 170 within the osteotomy isalso known, as defined by the dental plan for that patient.

FIG. 11 illustrates a flow chart 300 for use in creating a surgicalguide in accordance to the present invention. At step 302, a CT scan istaken of the region in the patient's mouth that will receive the dentalimplants. At step 304, a CT scan is taken of the patient's mouth in theopened position. Next, at step 306, the data from the CT scans at step302 and 304 is then imported into computer modeling software and used todevelop a 3-D virtual model of the patient's mouth. The data from the CTscans at step 302 and 304 is then merged, via a shape-matching algorithmto develop a unitary virtual model. The shape-matching algorithm, as iscommonly known in CAD/CAM and scanning systems, utilizes common features(e.g., bone, markers, teeth, scanning appliances, etc.) in the two scansto locate the relative position of one set of data to the other set ofdata. With the use of the virtual model created by the CT scans at step302 and 304, the surgical plan is developed along with the surgicalguide to be used with the surgical plan at step 306.

Based on the data from the second CT scan of step 304, theinstrumentation suggested for use in accordance with the surgical plancan be compared against the available dimensions within the patient'smouth. Thus, at step 308, the dimensions of the instrumentationsuggested for use with each implant in the surgical plan (according tosystem parameters) are compared against the available dimensions toensure that there will be no spatial problems encountered in thepatient's mouth. Accordingly, at step 310, if spatial problems areencountered, the surgical plan must be altered to ensure that no spatialproblems will be encountered during the actual surgery in the patient'smouth. As such, at step 312, for any implant that has encountered aproblem, the alterations related to the implant or the suggestedinstrumentation can occur. Examples of such alterations may include (i)changes to the size of the implant or the implant mount, (ii) changes tothe location (e.g., angular orientation and/or position) of the implantin the bone, (iii) changes to the surgical guide, and/or (iv) changes tothe instrumentation that is to be used for a certain implant.

Once the alteration of the surgical plan at step 312 has occurred, theinformation from the second CT scan is again used to ensure that thenewly suggested instrumentation (based on the alteration of the surgicalplan) will not cause spatial problems in the patient's mouth (i.e., step308 is repeated). If no spatial problems are encountered at step 310,then manufacturing data for the virtual surgical guide can be developedfor use in manufacturing the actual surgical guide, as in step 314. Oncethe actual surgical guide is manufactured, it can then be delivered tothe clinician for placement in the patient's mouth (as in step 314) andfor conducting surgery in accordance with the surgical plan derived fromthe virtual model.

Considering the various alterations that are possible at step 312, itshould be noted that some of those possible alterations inherentlyinvolve a change to the virtual surgical guide 50. For example, changesto the position and/or orientation of the virtual implant 70 will alsoinclude changes to the openings corresponding to the master tubes 120 inthe virtual surgical guide 50. On the other hand, some alterations maynot require a change to the virtual surgical guide 50. For example, if ashorter implant or a shorter implant mount is selected as an alteration,no alterations to the virtual surgical guide 70 may be needed. In afurther possible arrangement, only an alteration to the virtual surgicalguide may be necessary. For example, a spatial problem may be so minorthat simply altering the thickness of the surgical guide may be enoughto alleviate the problem. Or, changing the angle of an opening in thevirtual surgical guide may be enough to alleviate the problem.

In an alternative embodiment, the present invention contemplates the useof only a single scan with the mouth in the opened position. In otherwords, the single scan gathers enough information about the implantinstallation site, while also providing enough information about theopened-mouth condition that allows for the determination of spatiallimitations. Thus, when considering FIG. 11, step 302 would beunnecessary and, in step 306, the virtual model would be developed bythe single scan of the opened mouth.

If a single scan is used, then a need exists for providing a biteregistration between the upper jaw conditions and the lower jawconditions. One way to accomplish this task is by the use of a scanningappliance that has been modified to include material for the biteregistration. The scanning appliance for the patient may include a layerof barium sulfate of the modeled teeth structures such that the teethstructures are identified by the CT scan. Next, impression material isadded to the region of the scanning appliance at which the biteregistration for the opposing teeth is expected. The patient would thenclose his or her mouth to create the bite registration in the impressionmaterial on the scanning appliance. Once hardened, the impressionmaterial is then provided with a layer of barium sulfate (or othermaterial that is identifiable by the scan) at a different concentrationlevel so that the patient's bite registration can be independentlyidentified in the single CT scan and distinguished from the teethstructure on the scanning appliance. More information about CT-scanningand the use of scanning appliances can be found in the product brochureentitled “Simplant® SurgiGuide Cookbook” from Materialise US ClinicalServices, Inc., Glen Burnie, Md., which is herein incorporated byreference in its entirety. After the patient undergoes the single scanwith the mouth in the opened position using the scanning device havingthe bite registration, a virtual model of the patient's mouth in theclosed position can be created by merging the upper and lower conditionswith a shape-matching algorithm. The surgical plan can be developed, andthe instrumentation to be used in the surgical plan can be checked forspatial constraints, as described above. As such, the present inventioncontemplates the use of a scanning appliance that has been modified toinclude a representation of a bite registration.

It should also be noted that present invention contemplates the use ofvirtual modeling to develop a surgical plan that does not require theuse of a surgical guide. In other words, the CT-scans (or CT-scan) areused by the clinician to develop a virtual model indicating appropriatelocations for the implants based on the conditions in the patient'smouth. While no surgical guide is developed to dictate the exact angularposition and location of each implant in the patient's mouth, thevirtual model is still used for pre-operative visualization to determinewhether instrumentation will fit into the patient's mouth to place theimplants. If the spatial constraints indicate that instrumentation willnot fit, then changes to the instrumentation or the surgical plan may beneeded.

Similarly, the present invention contemplates the use of virtualmodeling to develop a non-dental implant surgical plan that measureswhether instrumentation will fit within the patient's mouth toaccomplish the non-dental implant surgical plan. Again, the virtualmodel is used for pre-operative visualization to determine whetherinstrumentation will fit into the patient's mouth when performing thenon-dental implant surgical plan.

While particular embodiments and applications of the present inventionhave been illustrated and described, it is to be understood that theinvention is not limited to the precise construction and compositionsdisclosed herein and that various modifications, changes, and variationsmay be apparent from the foregoing descriptions without departing fromthe spirit and scope of the invention as defined in the appended claims.

What is claimed is:
 1. A method of developing a surgical plan forperforming surgery in a patient's mouth, the method including:developing a virtual model of the patient's mouth on a computer systemby use of surgical-region data of a surgical region andopposing-condition data including dental conditions opposite thesurgical region, the virtual model being displayed on a displayassociated with the computer system; using the virtual model todetermine an available dimension from the surgical region to dentalstructures opposite the surgical region; using the virtual model tocheck dimensions of instrumentation to be used during the surgery toensure that the instrumentation will fit within the patient's mouthduring the surgery; and in response to the checking of the dimensions ofthe instrumentation indicating a workable condition, developing thesurgical plan from the virtual model, the surgical plan including asurgical protocol of the instrumentation to be used during the surgery.2. The method of claim 1, further comprising, in response to thechecking of the dimensions of the instrumentation indicating anunworkable condition, altering the instrumentation so that the alteredinstrumentation has a dimension that is less than the availabledimension.
 3. The method of claim 1, wherein the surgery includesplacing at least one dental implant in the patient's mouth.
 4. Themethod of claim 3, wherein the surgical plan further includes a locationof the at least one dental implant.
 5. The method of claim 3, furthercomprising developing a virtual surgical guide to be placed in thepatient's mouth, wherein, in response to the checking of the dimensionsof the instrumentation indicating an unworkable condition, altering thevirtual surgical guide.
 6. The method of claim 5, further comprisingmanufacturing a surgical guide to be placed in the patient's mouth basedon the altered virtual surgical guide.
 7. The method of claim 3,wherein, in response to the checking of the dimensions of theinstrumentation indicating an unworkable condition, altering the size ofat least one of the at least one dental implant.
 8. The method of claim1, further comprising displaying the instrumentation within the virtualmodel on the display.
 9. The method of claim 1, wherein one of thesurgical-region data and the opposing-condition data is obtained using aCT-scanner.
 10. The method of claim 1, wherein the dental conditionsopposite the surgical region include natural teeth or gingival tissue.11. The method of claim 1, further comprising manufacturing a surgicalguide based on the virtual model after the instrumentation is determinedto fit within the patient's mouth.
 12. A method of developing a surgicalplan for performing surgery in a patient's mouth, comprising: developinga virtual model of the patient's mouth on a computer system using (1)opposing-condition scan data from a scan of the patient's mouth in anopened position, the opposing-condition scan data including dentalconditions opposite the surgical region, and (2) bite registration databetween upper jaw conditions and lower jaw conditions, the virtual modelbeing displayed on a display; using the virtual model to determine anavailable dimension from the surgical region to dental structuresopposite the surgical region; using the virtual model to checkdimensions of instrumentation to be used during the surgery to ensurethat the instrumentation will fit within the patient's mouth during thesurgery; and in response to the checking of the dimensions of theinstrumentation indicating a workable condition, developing the surgicalplan from the virtual model, the surgical plan including a surgicalprotocol of the instrumentation to be used during the surgery.
 13. Themethod of claim 12, further comprising, in response to the checking ofthe dimensions of the instrumentation indicating an unworkablecondition, altering the instrumentation so that the alteredinstrumentation has a dimension that is less than the availabledimension.
 14. The method of claim 12, wherein the surgery includesplacing at least one dental implant in the patient's mouth.
 15. Themethod of claim 14, wherein the surgical plan further includes alocation of the at least one dental implant.
 16. The method of claim 14,further comprising developing a virtual surgical guide to be placed inthe patient's mouth, wherein, in response to the checking of thedimensions of the instrumentation indicating an unworkable condition,altering the virtual surgical guide.
 17. The method of claim 16, furthercomprising manufacturing a surgical guide to be placed in the patient'smouth based on the altered virtual surgical guide.
 18. The method ofclaim 14, wherein, in response to the checking of the dimensions of theinstrumentation indicating an unworkable condition, altering the size ofat least one of the at least one dental implant.
 19. The method of claim12, further comprising displaying the instrumentation within the virtualmodel on the display.
 20. The method of claim 12, wherein one of thesurgical-region data and the opposing-condition data is obtained using aCT-scanner.
 21. The method of claim 12, wherein the dental conditionsopposite the surgical region include natural teeth or gingival tissue.22. The method of claim 12, wherein the bite registration data isobtained from a CT-scan of a scanning appliance having impressionmaterial thereon, the impression material including the patient's biteregistration.
 23. The method of claim 12, further comprisingmanufacturing a surgical guide based on the virtual model after theinstrumentation is determined to fit within the patient's mouth.